[Interference of ethylene glycol on lactate assays]. / Interférences des métabolites de l'éthylène glycol avec les dosages du lactate.

Ethylene glycol is broken down to three main organic acids: glycolic acid, glyoxylic acid and oxalic acid which cause severe metabolic acidosis. Effect of these three acids on lactate assays was evaluated in five blood gas analysers and two clinical chemistry analysers. For all systems, no influence of oxalic acid on lactate results could be demonstrated. No interference of glycolic acid could be observed on lactate assay performed with Rapid Lab 1265 (R: 104,9 +/- 12,1%), Vitros 950 (R: 105,7 +/- 5,3 %) and Architect ci8200 (R: 104,9 +/- 4,7%), but on the contrary, CCX 4, OMNI S, ABL 725 and 825 demonstrated a concentration-dependent interference. No interference of glyoxylic acid could be observed with Vitros 950, but a positive interference could be observed with ABL 725 and 825, OMNI S, CCX4 and Architect ci8200 A linear relationship between apparent lactate concentration found with ABL 725 and 825, OMNI S, CCX 4, and glyoxylic acid could be observed (0,94 < r < 0,99), a weaker interference being observed with Rapid Lab 1265 and Architect ci 8200. Our results demonstrated that in case of ethylene glycol poisoning, cautious interpretation of lactate assay should be done, since wrong results of lactacidemia could lead to misdiagnostic and delay patient treatment.

[Multicenter evaluation of h-FABP semi-quantitative assay (Cardio Detect) in central laboratory: the point in acute myocardial infarction diagnosis]. / Evaluation multicentrique du dosage semi-quantitatif de la h-FABP (Cardio Detect) au laboratoire central : intérêt dans le diagnostic de l'infarctus du myocarde.

The diagnostic performance of heart-Fatty Acid Binding Protein (h-FABP) (semi-quantitative CardioDetect test) and cardiac troponin I (TnIc) blood assays were compared in one hundred patients presenting with suspicion of acute coronary syndrome. Final patient diagnosis was "acute myocardial infarction" in 36 cases, "non ST myocardial infarction" in 25 cases and "non ischemic pathologies" in 39 cases. h-FABP results were positive in 26 patients, negative in 57 patients and ambiguous in 17 patients, the latter corresponding to the final diagnosis of "acute myocardial infarction" in 5 cases, "non ST myocardial infarction" in 2 cases and "non ischemic pathologies " in 10 cases. At admission, h-FABP and TnIc exhibiteda sensitivity of 54% an 66%, respectively and a specificity of 86% and 95%, respectively. Positive and negative predictive values were 81% and 64% for h-FABP, respectively and 92% and 75% for cTnI, respectively. h-FABP and cTnI demonstrated a similar diagnostic efficiency if admission delay is less than 4 hours after onset of chest pain (area under ROC curve TnIc = 0.767 +/- 0.091 ; area under ROC curve h-FABP = 0.622 +/- 0.109 ; p = 0.144). On the contrary, cTnI assay demonstrated a better efficiency than h-FABP (p< 0.005) for patients admitted in a delay of 4 to 12 hours after the onset of chest pain. If chosen cTnI cut-off corresponded to the recent consensus definition used for monitoring acute coronary syndrome patients, h-FABP semi-quantitative assay realized within central laboratory did not demonstrated a better diagnostic efficiency than cTnI.

Frequency and prognostic value of cardiac troponin I elevation after coronary stenting.

Mild myocardial injuries after coronary angioplasty are associated with adverse late outcomes. The incidence and prognostic value of this phenomenon when using cardiac troponin I (cTnI) after stent implantation is unknown. We studied cTnI and creatine kinase (CK) release in 109 patients after stenting. Clinical success was achieved in 103 patients (94%). In-hospital major adverse coronary events were: death in 1 patient, Q-wave myocardial infarction in 1 patient, and non-Q-wave myocardial infarction in 2 patients. Twenty-nine patients (27%) had postprocedural cTnI increase, 16 (15%) had CK elevation. No preprocedural variables predicted marker elevation. Marker release was related to the occurrence of in-lab complications (59% vs 29% [p = 0.004 for cTnI] and 69% vs 32% [p = 0.011 for CK]). In 34% no explanation was found for cTnI increase. Success was more frequent in patients without cTnI elevation (100% vs 86%, p <0.001). The negative predictive value of cTnI increase was 100% for in-hospital major adverse coronary events (MACE), whereas its positive predictive value was 14%. cTnI and CK concordant elevation was associated with more intra- and postprocedural adverse events. During a mean follow-up of 8+/-3 months, major adverse coronary events were: death in 2 patients, myocardial infarction in 2 patients, and repeat PTCA in 8 patients. cTnI elevation was not predictive of these late MACE. cTnI elevation is common after stenting, and is related to the occurrence of in-lab complications. Its isolated elevation is not a good predictor of MACE. Patients with concordant cTnI and CK elevation seem to be at higher risk of in-hospital MACE.